Isolated cooling system having an insulator gap and front polarizer

ABSTRACT

An exemplary embodiment relates to a cooling system and a method for cooling an electronic display. A preferred embodiment includes a transparent gas cooling chamber. The transparent gas cooling chamber may have a linear polarizer. The components in the system are preferably housed within the electronic display housing. The cooling chamber defines a gas compartment that is anterior to and coextensive with the electronic display surface. Fans may be used to propel the isolated gas through the cooling chamber. The circulating gas removes heat directly from the electronic display surface by convection. The isolated gas is transparent or at least semi-transparent. The image quality of an exemplary embodiment remains essentially unchanged, even though the gas is flowing through a narrow channel over the visible face of the electronic display surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional patent application and claimspriority to U.S. Provisional Application Nos. 61/057,599 filed May 30,2008 and 61/039,454 filed Mar. 26, 2008 which are herein incorporated byreference in their entirety. This application is also a continuation inpart of U.S. patent application Ser. No. 11/941,728 filed Nov. 16, 2007,which is hereby incorporated by reference in its entirety. Thisapplication is also a continuation in part of U.S. patent applicationSer. No. 12/125,046 filed May 21, 2008, which is hereby incorporated byreference in its entirety. This application is also a continuation inpart of U.S. patent application Ser. No. 12/191,834 filed Aug. 14, 2008,which is hereby incorporated by reference in its entirety. Thisapplication is also a continuation in part of U.S. patent applicationSer. No. 12/234,307 filed Sep. 19, 2008, which is hereby incorporated byreference in its entirety. This application is also a continuation inpart of U.S. patent application Ser. No. 12/234,360 filed Sep. 19, 2008.This application is also a continuation in part of U.S. patentapplication Ser. No. 12/235,200 filed Sep. 22, 2008.

TECHNICAL FIELD

This invention generally relates to cooling systems. More particularly,exemplary embodiments relate to cooling systems for use with electronicdisplays, wherein the solar loading of the electronic display isreduced.

BACKGROUND AND SUMMARY OF THE INVENTION

Conductive and convective heat transfer systems for electronic displaysare known. These systems of the past generally attempt to remove heatfrom the electronic components in a display through as many sidewalls ofthe display as possible. In order to do this, the systems of the pasthave relied primarily on fans for moving air past the components to becooled and out of the display. In some cases, the heated air is movedinto convectively thermal communication with fins. Some of the pastsystems also utilize conductive heat transfer from heat producingcomponents directly to heat conductive housings for the electronics. Inthese cases, the housings have a large surface area, which is inconvective communication with ambient air outside the housings. Thus,heat is transferred convectively or conductively to the housing and isthen transferred into the ambient air from the housing by naturalconvection.

While such heat transfer systems have enjoyed a measure of success inthe past, improvements to displays require even greater coolingcapabilities.

In particular, cooling devices for electronic displays of the past havegenerally used convective heat dissipation systems that function to coolan entire interior of the display by one or more fans and fins, forexample. By itself, this is not adequate in many climates, especiallywhen radiative heat transfer from the sun through a display windowbecomes a major factor. In many applications and locations 200 Watts ormore of power through such a display window is common. Furthermore, themarket is demanding larger screen sizes for displays. With increasedelectronic display screen size and corresponding display window sizemore heat will be generated and more heat will be transmitted into thedisplays.

In the past, many displays have functioned satisfactorily with ten ortwelve inch screens. Now, many displays are in need of screens havingsizes greater than or equal to twenty-four inches that may requireimproved cooling systems. For example, some outdoor applications callfor forty-seven inch screens and above. With increased heat productionwith the larger screens and radiative heat transfer from the sun throughthe display window, heat dissipation systems of the past, which attemptto cool the entire interior of the display with fins and fans, are nolonger adequate.

A large fluctuation in temperature is common in the devices of the past.Such temperature fluctuation adversely affects the electronic componentsin these devices. Whereas the systems of the past attempted to removeheat only through the non-display sides and rear components of theenclosure surrounding the electronic display components, exemplaryembodiments cause convective heat transfer from the face of the displayas well. By the aspects described below, exemplary embodiments have madeconsistent cooling possible for electronic displays having screens ofsizes greater than or equal to twelve inches. For example, cooling of a55 inch screen can be achieved, even in extremely hot climates. Greatercooling capabilities are provided by the device and method described andshown in more detail below.

An exemplary embodiment relates to a front glass plate having apolarizer set in front of an electronic display so as to define aninsulator gap between the front glass plate and the electronic display.The front glass may be set forward of the electronic display surface byspacers defining the depth of the insulator gap. The depth of theinsulator gap may be adjusted depending on the application andenvironment in which the electronic display is used. The insulator gapmay be anterior and coextensive with the viewable face of the electronicdisplay surface. Because of the insulator gap the solar loadingoccurring on the front glass plate is not transferred to the electronicdisplay surface.

Another exemplary embodiment relates to an isolated gas cooling systemand a method for cooling an electronic display. An exemplary embodimentincludes an isolated gas cooling chamber. The gas cooling chamber ispreferably a closed loop which includes a first gas chamber comprising atransparent anterior plate and a second gas chamber comprising a coolingplenum. The first gas chamber is anterior to and coextensive with theviewable face of the electronic display surface. The transparentanterior plate may be set forward of the electronic display surface byspacers defining the depth of the first gas chamber. A cooling chamberfan, or equivalent means, maybe located within the cooling plenum. Thefan may be used to propel gas around the isolated gas cooling chamberloop. As the gas traverses the first gas chamber it contacts theelectronic display surface, absorbing heat from the surface of thedisplay. Because the gas and the relevant surfaces of the first gaschamber are transparent, the image quality remains excellent. After thegas has traversed the transparent first gas chamber, the gas may bedirected into the rear cooling plenum.

In order to cool the gas in the plenum, external convective orconductive means may be employed. In at least one embodiment, anexternal fan unit may also be included within the housing of thedisplay. The external fan unit may be positioned to provide a flow ofingested air over the external surfaces of the plenum. The heated air inthe housing may exit the housing as exhaust.

The first gas chamber may also act as an insulator for the electronicdisplay. In outdoor environments, radiative heat from the sun is a majorconcern. As the surface areas of displays are increased the amount ofsolar loading also increases. To combat this solar loading the claimedinvention provides a transparent anterior plate set forward of theelectronic display. This area between the transparent anterior plate andthe electronic display defines a first gas chamber. The gas chamber, aswell as carrying away heat generated by the electronic display, alsoacts as an insulating barrier between the transparent anterior plate andthe electronic display.

To further guard against solar loading of the electronic display, alinear polarizer may be employed at the transparent anterior plate. Thelinear polarizer serves to absorb a significant portion of the solarenergy, in-turn reducing the solar loading on the electronic display. Bysignificantly reducing the solar loading on the electronic displaythrough he use of a gas chamber and the linear polarizer either togetheror separately, the temperature of the electronic display issignificantly reduced. This reduction allows the cooling chamber tofunction more efficiently.

The foregoing and other features and advantages of the exemplaryembodiments will be apparent from the following more detaileddescription of the particular embodiments of the invention, asillustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of an exemplary embodiment will be obtained froma reading of the following detailed description and the accompanyingdrawings wherein identical reference characters refer to identical partsand in which:

FIG. 1 is a perspective view of an exemplary embodiment in conjunctionwith an exemplary electronic display.

FIG. 2 is an exploded perspective view of an exemplary embodimentshowing components of the isolated gas cooling system.

FIG. 3 is top plan view of an exemplary embodiment of the coolingchamber.

FIG. 4 is a front perspective view of an embodiment of the isolatedcooling chamber, particularly the transparent anterior surface of firstgas chamber.

FIG. 5 is a rear perspective view of an embodiment of the isolatedcooling chamber, particularly the cooling plenum.

FIG. 6 is a rear perspective view of an embodiment of the isolatedcooling chamber showing surface features that may be included on theplenum

FIG. 7 is a top plan view of an exemplary embodiment of the coolingchamber showing surface features that may be included on the plenum.

FIG. 8 is a front perspective view of an embodiment of the isolatedcooling chamber with included thermoelectric modules.

FIG. 9 is a top plan view of an exemplary embodiment of the coolingchamber with included thermoelectric modules.

FIG. 10 is an exploded perspective view of an exemplary embodimentshowing components of the isolated gas cooling system.

FIG. 11 is a cross-sectional top view through one exemplary embodiment.

FIG. 12 is a cross-sectional side view through the center of thedisplay.

FIG. 13 is a cross-sectional view through one exemplary embodiment.

FIG. 14 is a cross-sectional view through one exemplary embodiment.

FIG. 15 is a cross sectional view of another exemplary embodiment.

DETAILED DESCRIPTION

Exemplary embodiments relate to a cooling system for an electronicdisplay and to combinations of the cooling system and the electronicdisplay. Exemplary embodiments provide an isolated gas cooling systemfor an electronic display.

FIG. 1 illustrates an exemplary embodiment. As may be appreciated, whenthe display 10 is exposed to outdoor elements, the temperatures insidethe display 10 will vary greatly without some kind of cooling device. Assuch, the electronics including the display screen (e.g., LCD screen)will have a greatly reduced life span. By implementing certainembodiments of the cooling system disclosed herein, temperaturefluctuation is greatly reduced. This cooling capability has beenachieved in spite of the fact that larger screens generate more heatthan smaller screens.

The display shown is equipped with an innovative gas cooling system.Accordingly, it may be placed in direct sunlight. Although the coolingsystem may be used on smaller displays, it is especially useful forlarger LCD, LED, or organic light emitting diodes (OLED) displays. Thesescreens, especially with displays over 24 inches, face significantthermoregulatory issues in outdoor environments.

In FIG. 1, the display area of the electronic display shown includes anarrow gas chamber that is anterior to and coextensive with theelectronic display surface. The display shown also is equipped with anoptional air curtain device 114 which is the subject matter ofco-pending U.S. application Ser. No. 11/941,728, incorporated byreference herein. Optionally, the display also has a reflection shield119, to mitigate reflection of the sunlight on the display surface.Additionally, in outdoor environments, housing 70 is preferably a colorwhich reflects sunlight.

It is to be understood that the spirit and scope of the disclosedembodiments includes cooling of displays including, but not limited toLCDs. By way of example and not by way of limitation, exemplaryembodiments may be used in conjunction with displays selected from amongLCD (including TFT or STN type), light emitting diode (LED), organiclight emitting diode (OLED), field emitting display (FED), cathode raytube (CRT), and plasma displays. Furthermore, exemplary embodiments maybe used with displays of other types including those not yet discovered.In particular, it is contemplated that exemplary embodiments may be wellsuited for use with full color, flat panel OLED displays. While theembodiments described herein are well suited for outdoor environments,they may also be appropriate for indoor applications (e.g., factoryenvironments) where thermal stability of the display may be at risk.

As shown in FIG. 2 an exemplary embodiment 10 of the electronic displayand gas cooling system includes an isolated gas cooling chamber 20contained within an electronic display housing 70. A narrow transparentfirst gas chamber is defined by spacers 100 and transparent first frontplate 90. A transparent second front glass 130 may be laminated to thefirst front glass 90 to help prevent breakage of the first front glass90. As shown in FIG. 2, cooling chamber 20 surrounds and LCD stack 80and associated backlight panel 140.

The gas cooling system 10 shown in FIG. 2 may include means for coolinggas contained within the second gas chamber. These means may include afan 60 which may be positioned at the base of the display housing 70.The fan will force the cooler ingested air over at least one externalsurface of a posterior cooling plenum 45. If desired, an air conditioner(not shown) may also be utilized to cool the air which contacts theexternal surface of plenum 45.

Referring to FIG. 3, in at least one embodiment the isolated gas coolingchamber 20 comprises a closed loop which includes a first gas chamber 30(see FIG. 3) and a second gas chamber 40. The first gas chamber 30includes a transparent first front glass 90. The second gas chamber 40comprises a cooling plenum 45. The term “isolated gas” refers to thefact that the gas within the isolated gas cooling chamber 20 isessentially isolated from external air in the housing of the display.Because the first gas chamber 30 is positioned in front of the displayimage, the gas should be substantially free of dust or othercontaminates that might negatively affect the display image.

The isolated gas may be almost any transparent gas, for example, normalair, nitrogen, helium, or any other transparent gas. The gas ispreferably colorless so as not to affect the image quality. Furthermore,the isolated gas cooling chamber need not necessarily be hermeticallysealed from the external air. It is sufficient that the gas in thechamber is isolated to the extent that dust and contaminates may notsubstantially enter the first gas chamber.

In the closed loop configuration shown in FIG. 3, the first gas chamber30 is in gaseous communication with the second gas chamber 40. A coolingchamber fan 50 may be provided within the posterior plenum 45. Thecooling fan 50 may be utilized to propel gas around the isolated gascooling chamber 20. The first gas chamber 30 includes at least one firstfront glass 90 mounted in front of an electronic display surface 85. Thefirst front glass 90 may be set forward from the electronic displaysurface 85 by spacers 100 (see FIG. 4). The spacing members 100 definethe depth of the narrow channel passing in front of the electronicdisplay surface 85. The spacing members 100 may be independent oralternatively may be integral with some other component of the device(e.g., integral with the front plate). The electronic display surface85, the spacing members 100, and the transparent first front plate 90define a narrow first gas chamber 30. The chamber 30 is in gaseouscommunication with plenum 45 through entrance opening 110 and exitopening 120.

As shown in FIG. 3, a posterior surface of the first gas chamber 30preferably comprises the electronic display surface 85 of the displaystack 80. As the isolated gas in the first gas chamber 30 traverses thedisplay it contacts the electronic display surface 85. Contacting thecooling gas directly to the electronic display surface 85 enhances theconvective heat transfer away from the electronic display surface 85.

Advantageously, in exemplary embodiments the electronic display surface85 comprises the posterior surface of the first gas chamber 30.Accordingly, the term “electronic display surface” refers to the frontsurface of a typical electronic display (in the absence of theembodiments disclosed herein). The term “viewable surface” or “viewingsurface” refers to that portion of the electronic display surface fromwhich the electronic display images may be viewed by the user.

The electronic display surface 85 of typical displays is glass. However,neither display surface 85, nor transparent first front glass 90, noroptional transparent second front glass 130 need necessarily be glass.Therefore, the term “glass” will be used herein interchangeably with theterm plate. By utilizing the electronic display surface 85 as theposterior surface wall of the gas compartment 30, there may be fewersurfaces to impact the visible light traveling through the display.Furthermore, the device will be lighter and cheaper to manufacturer.

Although the embodiment shown utilizes the electronic display surface85, certain modifications and/or coatings (e.g., anti-reflectivecoatings) may be added to the electronic display surface 85, or to othercomponents of the system in order to accommodate the coolant gas or toimprove the optical performance of the device. In the embodiment shown,the electronic display surface 85 may be the front glass plate of aliquid crystal display (LCD) stack. However, almost any display surfacemay be suitable for embodiments of the present cooling system. Althoughnot required, it is preferable to allow the cooling gas in the first gaschamber 30 to contact the electronic display surface 85 directly. Inthis way, the convective effect of the circulating gas will bemaximized. Preferably the gas, which has absorbed heat from theelectronic display surface 85 may then be diverted to the cooling plenum45 where the collected heat energy in the gas may be dissipated into theair within the display housing 70 by conductive and or convective means.

To prevent breakage, the optional second front glass 130 may be adheredto the front surface of the first front glass 90. Alternatively firstfront glass 90 may be heat tempered to improve its strength. As shown inFIG. 3, fan 50 propels a current of air around the loop (see arrows) ofthe isolated gas cooling chamber 20. The plenum 45 defining the secondgas chamber 40 is adapted to circulate the gas behind the electronicdisplay surface 85. The plenum 45 preferably surrounds most of the heatgenerating components of the electronic display, for example, backlightpanel 140 (e.g., an LED backlight).

FIG. 4 shows that the first front glass 90 helping define the first gaschamber 30 is transparent and is positioned anterior to and at leastcoextensive with a viewable area of an electronic display surface 85.The arrows shown represent the movement of the isolated gas through thefirst gas chamber 30. As shown, the isolated gas traverses the first gaschamber 30 in a horizontal direction. Although cooling system 20 may bedesigned to move the gas in either a horizontal or a vertical direction,it is preferable to propel the gas in a horizontal direction. In thisway, if dust or contaminates do enter the first gas chamber 30, theywill tend to fall to the bottom of chamber 30 outside of the viewablearea of the display. The system may move air left to right, oralternatively, right to left.

As is clear from FIG. 4, to maximize the cooling capability of thesystem, the first gas chamber 30 preferably covers the entire viewablesurface of the electronic display surface 85. Because the relevantsurfaces of the first gas chamber 30 as well as the gas containedtherein are transparent, the image quality of the display remainsexcellent. Anti-reflective coatings may be utilized to minimize specularand diffuse reflectance. After the gas traverses the first gas chamber30 it exits through exit opening 120. Exit opening 120 defines theentrance junction into the rear cooling plenum 45.

FIG. 5 shows a schematic of the rear cooling plenum 45 (illustrated astransparent for explanation). One or more fans 50 within the plenum mayprovide the force necessary to move the isolated gas through theisolated gas cooling chamber. Whereas the first gas chamber 30 wasdesigned to collect heat from the surface 85 of the display, the secondgas chamber 40 is designed to dissipate that heat into the housing 70.Plenum 45 may have various contours and features to accommodate theinternal structures within a given electronic display application. FIGS.11 and 12 demonstrates one such alternative embodiment.

As can be discerned in FIGS. 6 and 7, various surface features 150 maybe added to improve heat dissipation from the plenum 45. These surfacefeatures 150 provide more surface area to radiate heat away from the gaswithin the second gas chamber 40. These features 150 may be positionedat numerous locations on the surface of the plenum 45.

Referring to FIGS. 8 and 9, one or more thermoelectric modules 160 maybe positioned on at least one surface of the plenum 45 to further coolthe gas contained in the second gas chamber 40. The thermoelectricmodules 160 may be used independently or in conjunction with surfacefeatures 150. Alternatively, thermoelectric modules 160 may be useful toheat the gas in the rear plenum if the unit is operated in extreme coldconditions.

FIG. 10 shows an exemplary method for removing heat in the gas containedin the rear plenum 45. Fan 60 may be positioned to ingest external airand blow that air into the display housing 70. Preferably, the air willcontact the anterior and posterior surfaces of the plenum 45.Furthermore, in this configuration, fan 60 will also force fresh airpast the heat generating components of the electronic display (e.g., theTFT layer and the backlight) to further improve the cooling capabilityof the cooling system. The heated exhaust air may exit through one ormore apertures 179 located on the display housing 70.

Besides thermoelectric modules 160, there are a number of ways to coolthe gas in the second gas chamber. For example air conditioners or othercooling means known by those skilled in the art may be useful forcooling the gas contained in plenum 45.

FIG. 11 is a cross-sectional top view of an exemplary embodiment. Notethat plenum 45 may have many possible shapes. In FIG. 11, the plenumtapers to allow for the placement of DC power converters.

FIG. 12 shows a side cross-section view of the embodiment shown in FIG.11. In the arrangement shown, a fan unit 60 forces a flow of ingestedair into the display housing 70. The air travels upward along both sidesof plenum 45. In the exemplary embodiment shown in FIG. 12, the exhaustair is directed to exit toward the top-front of the display housing. Inthe embodiment shown, an optional air curtain device 114, described inCo-pending application Ser. No. 11/941,728, is included to direct theexhaust air back across the external surface of the first front glass 90(or second front glass 130) of the cooling chamber. The external currentof exhaust air may assist in removing even more heat from the electronicdisplay surface 85. This embodiment also has an optional reflectionshield 119 to help reduce reflection caused by the sun.

While the display is operational, the isolated gas cooling system mayrun continuously. However, if desired, a temperature sensor (not shown)and a switch (not shown) may be incorporated within the electronicdisplay 10. The thermostat may be used to detect when temperatures havereached a predetermined threshold value. In such a case, the isolatedgas cooling system may be selectively engaged when the temperature inthe display reaches a predetermined value. Predetermined thresholds maybe selected and the system may be configured with a thermostat (notshown) to advantageously keep the display within an acceptabletemperature range.

An optional air filter (not shown) may be employed within the plenum toassist in preventing contaminates and dust from entering the first gaschamber 30.

In other embodiments, the electronics may be included in the isolatedcooling system, such as described in Co-pending application Ser. No.12/234,360.

FIG. 13 is a cross-sectional view of an exemplary embodiment. In thearrangement shown, a first front glass 90 and a second front glass 130may be laminated together. The first and second front glass 130 and 90may be fixed to one another with a layer of index matched opticaladhesive 200 to form a front glass unit 206. The first and second frontglasses 130 and 90 may be laminated to one another through the processdescribed in U.S. application Ser. No. 12/125,046. The LCD stack maycomprise an electronic display 212 interposed between a front polarizer216 and a rear polarizer 214. In other embodiments, the LCD may be anylayer or surface used to construct an electronic display. The LCD stack80 and the front glass unit 206 define an insulator gap 300. The depthof the insulator gap 300 may be controlled by spacers 100 (shown in FIG.2). The insulator gap 300 serves to thermally separate the front glassunit 206 from the LCD stack 80. This thermal separation localizes theheat on the front glass unit rather than allowing solar loading of theLCD stack. In some embodiments, the insulator gap 300 may be devoid ofany gaseous material. In other embodiments, the insulator gap 300 may bethe first gas chamber 30. In other embodiments, the insulator gap 300may be filled with any substantially transparent gas.

The second front glass may have a first surface 202 and a second surface208. The first surface 202 may be exposed to the elements; while thesecond surface 208 may be fixed to the first front glass 90 by the indexmatched optical adhesive 200. The first front glass may have a thirdsurface 210 and a fourth surface 204. The third surface 210 may be fixedto the second front glass 130 by the index matched optical adhesive 200;while the fourth surface may be directly adjacent to the insulator gap300. In some embodiments, to decrease the solar loading of the LCD stack80 and improve the viewable image quality, an anti-reflective coatingmay be applied to the first surface 202 and the fourth surface 204. Inother embodiments, the anti-reflective coating may only be applied to atleast one of the first, second, third, or fourth surface 202, 208, 210,and 204.

FIG. 14 is a cross-sectional view of another exemplary embodiment of thefront glass unit 206. In the arrangement shown, the front glass unit 206comprises a second front glass 130, a layer of index matched opticaladhesive 200, a linear polarizer 400, and a first glass surface 90. Thelinear polarizer 300 may be bonded to the first, second, third or fourthsurface 202, 208, 210, and 204. The linear polarizer 300 may be alignedwith the front polarizer 210 found in the LCD stack 85. The inclusion ofa linear polarizer 400 in the front glass unit 206, further decreasesthe solar load on the LCD stack 80. The reduction in solar loading maysignificantly reduce the temperature of the electronic display.

The inclusion of the linear polarizer 400 may not affect the viewingangle of the electronic display or the chromaticity over angle. Anotherbeneficial aspect of including the linear polarizer 300 is a reductionin specular reflection of the front glass unit 206 and the LCD stack 80by approximately 50%.

FIG. 15 illustrates a cross sectional view of another exemplaryembodiment. In the arrangement shown, a front glass 600 is positionedanterior to an LCD stack 80. The front glass 600 and LCD stack define aninsulator gap 300. The front glass 600 and the LCD stack 80 are not incontact with one another as in other exemplary embodiments. The frontglass 600 may have a first surface 602 and a second surface 604. Thefront glass 600 may also have a linear polarizer 400 on the either thefirst or second surfaces 602 and 604. In some exemplary embodiments, theinsulator gap 300 may be a first gas chamber 30. As in other exemplaryembodiments, the LCD stack 80 may include multiple layers forming aviewable display.

It should be understood that the LCD stack 80 may be replaced with anyother type of electronic display, including, but not limited to, plasmadisplays, organic light emitting diode (OLED), CRT, and rear or frontprojection,

Having shown and described a preferred embodiment of the invention,those skilled in the art will realize that many variations andmodifications may be made to affect the described invention and still bewithin the scope of the claimed invention. Additionally, many of theelements indicated above may be altered or replaced by differentelements which will provide the same result and fall within the spiritof the claimed invention. It is the intention, therefore, to limit theinvention only as indicated by the scope of the claims.

What is claimed is:
 1. A cooling system for an electronic display havinga viewable area, the system comprising: a front glass unit positioned infront of the viewable area of the electronic display, the front glassunit including: a first front glass having a first and second surface; asecond front glass having a third and fourth surface, bonded to thefirst front glass; a linear polarizer disposed on at least one of thesurfaces; a first gas chamber positioned anterior to the viewable areaof the electronic display; a second gas chamber positioned posterior tothe viewable area of the electronic display and operatively connected tothe first gas chamber to provide a closed loop for circulating gas; anda fan positioned to force ambient air between the first and second gaschambers such that the ambient air does not mix with the circulatinggas.
 2. The cooling system of claim 1, wherein the linear polarizer isinterposed between the first and second front glasses.
 3. The coolingsystem of claim 1, wherein the first and second front glasses are bondedtogether with an index matched optical adhesive.
 4. The cooling systemof claim 1, further comprising an anti-reflective coating on the firstand second front glasses.
 5. The cooling system of claim 1, furthercomprising a fan to propel gas through the first and second gaschambers.
 6. The cooling system of claim 1, further comprising a meansfor cooling gas contained within the second gas chamber.
 7. The coolingsystem of claim 1, further comprising spacers interposed between thefront glass unit and the electronic display defining the depth of thefirst gas chamber.
 8. A cooling system for an electronic display havinga viewable area and a rear surface, the system comprising: a front glassunit, including: a first front glass having a first and second surface;a second front glass having a third and fourth surface, bonded to thefirst front glass; a linear polarizer disposed on at least one of thesurfaces; and a fan positioned to force ambient air along the rearsurface of the electronic display; wherein the front glass unit ispositioned in front of the electronic display to define a first gaschamber positioned anterior to the viewable area of the electronicdisplay; a second gas chamber positioned posterior to the viewable areaof the electronic display and operatively connected to the first gaschamber so that gas may circulate through the first and second gaschamber; and wherein the ambient air is not permitted to enter the firstgas chamber.
 9. The cooling system of claim 8, wherein the linearpolarizer is interposed between the first and second front glasses. 10.The cooling system of claim 8, wherein the first and second frontglasses are bonded together with an index matched optical adhesive. 11.The cooling system of claim 8, further comprising an anti-reflectivecoating on the first and second front glasses.
 12. The cooling system ofclaim 8, further comprising a fan to propel gas through the first andsecond gas chambers.
 13. The cooling system of claim 8, furthercomprising a means for cooling gas contained within the second gaschamber.
 14. A liquid crystal display assembly comprising: a liquidcrystal stack having a front polarizer and rear polarizer; a backlightpositioned behind the liquid crystal stack and having a rear surfacefacing away from the liquid crystal stack; a fan positioned to forceambient air along the rear surface of the backlight such that ambientair contacts the rear surface of the backlight; a front glass unitplaced in front of the front polarizer and comprising a first frontglass panel, a second front glass panel bonded to the first front glasspanel, and an additional linear polarizer aligned with the frontpolarizer and placed between the first and second front glass panels;and an insulator gap placed between the front glass unit and the frontpolarizer, wherein the insulator gap is a first gas chamber positionedanterior to a viewable area of the liquid crystal stack; a second gaschamber positioned posterior to the viewable area of the liquid crystalstack and operatively connected to the first gas chamber to form aclosed loop for circulating gas; and wherein the ambient air is notpermitted to enter the insulator gap.
 15. The liquid crystal displayassembly of claim 14 further comprising: an anti reflective coating onthe first front glass panel.
 16. The liquid crystal display assembly ofclaim 14 further comprising: an anti reflective coating on the secondfront glass panel.
 17. The liquid crystal display assembly of claim 14further comprising: a fan positioned to drive the circulating gas aroundthe closed loop.
 18. The liquid crystal display assembly of claim 17further comprising: a means for cooling the circulating gas.
 19. Theliquid crystal display assembly of claim 17 further comprising: a plenumplaced behind the liquid crystal stack and accepting the circulatinggas.
 20. The liquid crystal display assembly of claim 19 furthercomprising: a fan positioned to draw external air over the plenum.